[FEATURE] TNS command for screen recording on-device

Hey Nativescript team,

As always thanks for all the hard work -- using Nativescript Vue and enjoying it immensely!

After being thoroughly impressed by the tns resources splashes generate command, I thought it would be great to have a tns subcommand that started/stopped/extracted screen recordings from a device. It's not hard to do with recent versions of android (adb shell screenrecording /sdcard/whatever.mp4), but it might be even more convenient to use a tns command to do it (and pull out the file afterwards).

(I hope I'm filing this feature request properly -- none of the template instructions seemed to deal with feature requests, it was all about what to put for but reports...)

Beginne damit, den vorhandenen Befehl tns resources splashes generate und die Art zu untersuchen, wie die CLI Android-Gerätebefehle aufruft. Vergleiche diesen Ablauf mit adb shell screenrecording /sdcard/whatever.mp4, einschließlich des Abrufens der resultierenden Datei. Die Aufgabe ist erledigt, wenn ein tns-Unterbefehl eine Aufzeichnung auf dem Gerät starten, stoppen und extrahieren kann.